Oven for heating food

CROSS-REFERENCE TO RELATED APPLICATION

0001This application is a continuation application claiming priority to PCT Application No. PCT/US2011/028786 filed Mar. 17, 2011, the entirety of which is hereby incorporated by reference.

FIELD OF THE INVENTION

0002The present invention generally relates to food serving equipment, and more particularly to an oven for heating food.

BACKGROUND OF THE INVENTION

0003In one embodiment, this invention is directed to an oven which uses hot gas to maintain pre-cooked food at proper temperatures before serving. This type of equipment is often referred to using such terms as a holding oven, or a holding unit, or a food warmer. Such equipment is used in the fast food service industry to heat food prior to serving it.

SUMMARY OF THE INVENTION

0004In one embodiment, this invention is directed to an oven for heating food, comprising a housing having a left side, a right side, a top, a bottom, a back, and a front. The housing defines an oven cavity comprising at least one heating compartment for heating food placed in the compartment. The heating compartment has a left side wall, a right side wall, a back wall, a top wall, a bottom wall, and an open front, without a door, in open communication with a surrounding environment outside the oven. Gas flow openings are provided in the left and right side walls. The oven includes a blower for blowing gas through the gas flow openings into the heating compartment, and a heater for heating gas blowing into the heating compartment through the openings. The gas flow openings are configured such that substantially all of the gas blowing into the heating compartment is directed generally away from the open front of the compartment.

0005In another embodiment, this invention is directed to an oven for heating food, comprising a housing having a left side, a right side, a top, a bottom, a back, and a front. The housing defines an oven cavity comprising at least one heating compartment for heating food placed in the compartment. The heating compartment has a left side wall, a right side wall, a back wall, a top wall, a bottom wall, and an open front, without a door, in open communication with a surrounding environment outside the oven. Gas flow openings are provided in the left and right side walls. The oven includes a blower for blowing gas through the gas flow openings into the heating compartment, and a heater for heating gas blowing into the heating compartment through the openings. A movable air deflector at the top of the open front of the heating compartment is provided for deflecting heated air into the heating compartment. The air deflector is movable between a lowered operative position and a raised position. In its lowered position, the air deflector extends down over only an upper portion of the open front of the heating compartment.

0006In another embodiment, this invention is directed to an oven for heating food, comprising a housing having a left side, a right side, a top, a bottom, a back, and a front. The housing defines an oven cavity comprising at least one heating compartment for heating food placed in the compartment. The heating compartment has a left side wall, a right side wall, a back wall, a top wall, a bottom wall, and an open front, without a door, in open communication with a surrounding environment outside the oven. Gas flow openings are provided in the left and right side walls. The oven includes a blower for blowing gas through the gas flow openings into the heating compartment, and a heater for heating gas blowing into the heating compartment through the openings. The heating compartment has a side-to-side width of no more than about 14 inches. A gas dead zone at the front of the heating compartment extends substantially an entire height of the compartment and a full side-to-side width of the compartment and having a dimension in front-to-rear direction of at least 2 in. The gas dead zone is substantially free of moving gas generated by the oven during operation of the oven to heat food in the heating compartment.

0007In yet another embodiment, this invention is directed to an oven for heating food, comprising a housing having a left side, a right side, a top, a bottom, a back, and a front. The oven includes an oven cavity inside the housing comprising at least one heating compartment for heating food placed in the compartment. The heating compartment has a left side wall, a right side wall, a back wall, and an open front, without a door, in open communication with a surrounding environment outside the oven. Gas flow openings are provided in at least one of the left and right side walls. A blower is provided for blowing gas through said gas flow openings in at least one of the left and right side walls into the heating compartment. A heater is provided for heating gas blowing into the heating compartment through said gas flow openings in at least one of the left and right side walls. Gas flow openings are provided in the back wall of the heating compartment. Gas blows into the heating compartment via said gas flow openings in at least one of the left and right side walls, and gas exhausts from the heating compartment via said gas flow openings in the back wall of the heating compartment.

0008Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

0009<figref idref="DRAWINGS">FIG. 1</figref> is a perspective of a first embodiment of an oven of this invention;

0010<figref idref="DRAWINGS">FIG. 2</figref> is a front elevation of the oven;

0011<figref idref="DRAWINGS">FIG. 3</figref> is horizontal section taken in the plane of <b>3</b>-<b>3</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

0012<figref idref="DRAWINGS">FIG. 4</figref> is a vertical section taken in the plane of <b>4</b>-<b>4</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

0013<figref idref="DRAWINGS">FIG. 5</figref> is a vertical section taken in the plane of <b>5</b>-<b>5</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

0014<figref idref="DRAWINGS">FIG. 6</figref> is a vertical section taken in the plane of <b>6</b>-<b>6</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

0015<figref idref="DRAWINGS">FIG. 7</figref> is a vertical section taken in the plane of <b>7</b>-<b>7</b> in <figref idref="DRAWINGS">FIG. 2</figref>;

0016<figref idref="DRAWINGS">FIG. 8</figref> is an elevation of the back wall a heating compartment of the oven;

0017<figref idref="DRAWINGS">FIG. 9</figref> is a perspective view of the oven of <figref idref="DRAWINGS">FIG. 1</figref> but with top portions of the oven removed to show details;

0018<figref idref="DRAWINGS">FIG. 10</figref> is a top view of <figref idref="DRAWINGS">FIG. 9</figref>;

0019<figref idref="DRAWINGS">FIG. 11</figref> is a perspective view showing food-holding trays positioned in the heating compartments;

0020<figref idref="DRAWINGS">FIG. 12</figref> is a perspective view of a side wall panel of a heating compartment;

0021<figref idref="DRAWINGS">FIG. 13</figref> is a top view similar to <figref idref="DRAWINGS">FIG. 3</figref>; showing a dead zone of the oven;

0022<figref idref="DRAWINGS">FIG. 14</figref> is a perspective view of a second embodiment of a side wall panel of a heating compartment;

0023<figref idref="DRAWINGS">FIG. 15</figref> is a front perspective of the oven;

0024<figref idref="DRAWINGS">FIG. 16</figref> is a front elevation of the oven of <figref idref="DRAWINGS">FIG. 15</figref>;

0025<figref idref="DRAWINGS">FIG. 17</figref> is a vertical sectional view taken through the oven in a plane extending in front-to-back direction showing the flow of heated air through a heating compartment of the oven;

0026<figref idref="DRAWINGS">FIG. 18</figref> is a front perspective view of a second embodiment of an oven of this invention;

0027<figref idref="DRAWINGS">FIG. 19</figref> is a vertical section taken in the plane of <b>19</b>-<b>19</b> in <figref idref="DRAWINGS">FIG. 18</figref>;

0028<figref idref="DRAWINGS">FIG. 19A</figref> is a perspective of one embodiment of a tray that can be used in the oven;

0029<figref idref="DRAWINGS">FIG. 20</figref> is a vertical section taken in the plane of <b>20</b>-<b>20</b> in <figref idref="DRAWINGS">FIG. 18</figref>;

0030<figref idref="DRAWINGS">FIG. 21</figref> is a view similar to <figref idref="DRAWINGS">FIG. 18</figref> but with top portions of the oven removed to show details;

0031<figref idref="DRAWINGS">FIG. 22</figref> is a top view of <figref idref="DRAWINGS">FIG. 20</figref>;

0032<figref idref="DRAWINGS">FIG. 23</figref> is an enlarged cross-sectional view of a gas flow opening in a side wall of a heating compartment;

0033<figref idref="DRAWINGS">FIG. 24</figref> is a front perspective view of a third embodiment of an oven of this invention;

0034<figref idref="DRAWINGS">FIG. 25</figref> is a vertical section taken in the plane of <b>25</b>-<b>25</b> in <figref idref="DRAWINGS">FIG. 24</figref>; and

0035<figref idref="DRAWINGS">FIG. 26</figref> is a vertical section taken in the plane of <b>26</b>-<b>26</b> in <figref idref="DRAWINGS">FIG. 24</figref>.

0036Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

0037Referring now to the drawings, and more particularly to <figref idref="DRAWINGS">FIGS. 1-3</figref>, an oven of this invention for heating food with heated gas (e.g., air) is designated in its entirety by the reference number <b>20</b>. The oven comprises a housing <b>22</b> having an outer box-like shell <b>24</b> with a left side <b>26</b>, a right side <b>28</b>, a top <b>32</b>, a bottom <b>34</b>, a back <b>36</b>, and a front <b>38</b> which is partially open. The housing <b>24</b> also includes an inner shell or liner <b>40</b> spaced inward from the sides <b>26</b>, <b>28</b>, back <b>36</b> and top <b>32</b> of the outer shell <b>24</b> to form a space <b>42</b> for receiving suitable thermal insulation (see <figref idref="DRAWINGS">FIG. 3</figref>). A louvered vent <b>43</b> is provided in the top <b>32</b> of the outer shell <b>24</b> for venting the space <b>42</b>.

0038The housing <b>22</b> defines an oven cavity <b>44</b> comprising at least one heating compartment <b>46</b> inside the liner <b>40</b>. In this particular embodiment, the cavity <b>44</b> comprises two side-by-side heating compartments, namely, a left heating compartment <b>46</b> and a right heating compartment <b>50</b>. The number and arrangement of heating compartments can vary. By way of example, the compartments may be arranged in vertical columns and horizontal rows, and the number of compartments in each column and each row may vary from one to two or more. The outer shell <b>24</b> and liner <b>40</b> of the housing <b>22</b> are constructed of suitable material, such as sheet metal.

0039The left heating compartment <b>46</b> is generally rectangular and is defined by a left side wall comprising a left side wall panel <b>54</b>, a right side wall comprising a right side panel <b>58</b>, a back wall comprising a back panel <b>62</b>, a top wall comprising a top panel <b>66</b>, and a bottom wall comprising a bottom wall panel <b>70</b> spaced above the bottom <b>34</b> of the housing <b>24</b>. The front of the left heating compartment <b>46</b> is open to the environment surrounding the oven. The left side panel <b>54</b> of the left heating compartment <b>46</b> is spaced from the inner liner <b>40</b> to define a left side gas plenum <b>72</b>.

0040Similarly, the right heating compartment <b>50</b> is generally rectangular and defined by a left side wall comprising a left side wall panel <b>80</b>, a right side wall comprising a right side panel <b>84</b>, a back wall comprising back panel <b>88</b> (which may be an integral extension of the back panel <b>62</b> of the left heating compartment <b>46</b>), a top wall comprising a top panel <b>92</b> (which may be an integral extension of the top panel <b>66</b> of the left heating compartment <b>46</b>), and a bottom wall comprising a bottom wall panel <b>96</b> spaced above the bottom <b>34</b> of the housing <b>24</b>. The front of the right heating compartment <b>50</b> is open to the environment surrounding the oven. The right side panel <b>84</b> of the right heating compartment <b>50</b> is spaced from the inner liner <b>40</b> to define a right side gas plenum <b>98</b>. The right wall <b>58</b> of the left heating compartment <b>46</b> is spaced from the left wall <b>80</b> of the right heating compartment to define an intermediate gas plenum <b>102</b> between the two heating compartments that extends the full heights of the heating compartments <b>46</b>, <b>50</b> (see <figref idref="DRAWINGS">FIG. 3</figref>).

0041In the illustrated embodiment, the back panels <b>62</b>, <b>88</b> of the two heating compartments <b>46</b>, <b>50</b> are spaced forward of the inner liner <b>40</b> of the housing <b>22</b> to define a back gas plenum <b>106</b>. Similarly, the top panels <b>66</b>, <b>92</b> of the two heating compartments <b>46</b>, <b>50</b> are spaced below the inner liner <b>40</b> to define a top gas plenum <b>110</b>.

0042The various panels forming the gas plenums of the oven are of suitable material, such as sheet metal.

0043The walls of each heating compartment <b>46</b>, <b>50</b> are provided with gas flow openings <b>120</b>, <b>124</b> for the circulation of hot gas into and out of the compartment. In particular, the left and right side walls <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> of each compartment are provided with side wall openings <b>120</b>, and the back wall <b>62</b>, <b>88</b> of each heating compartment is provided with back wall openings <b>124</b> (<figref idref="DRAWINGS">FIG. 8</figref>). As best shown in <figref idref="DRAWINGS">FIGS. 9 and 10</figref>, the top panels <b>66</b>, <b>92</b> forming the top walls of the two heating compartments <b>46</b>, <b>50</b> have side openings <b>130</b> that communicate with respective left and right gas plenums <b>72</b>, <b>98</b> of the heating compartments, and intermediate openings <b>134</b> that communicate with the intermediate gas plenum <b>102</b>.

0044The back gas plenum <b>106</b> is divided by a pair of spaced vertical partitions <b>140</b> into a left gas flow channel <b>142</b>L communicating with the left heating compartment <b>46</b> and the top gas plenum <b>110</b>, and a right gas flow channel <b>142</b>R, separate from the left gas flow channel <b>142</b>L, communicating with the right heating compartment <b>50</b> and the top gas plenum. As illustrated best in <figref idref="DRAWINGS">FIGS. 4 and 6</figref>, each of these flow channels <b>142</b>L, <b>142</b>R extends substantially the full height of a respective compartment <b>46</b>, <b>50</b>. The flow channels communicate with respective heating compartments <b>46</b>, <b>50</b> through the openings <b>124</b> in the back panels <b>62</b>, <b>88</b>. Essentially all gas exiting the left heating compartment <b>46</b> flows into the left gas flow channel <b>142</b>L, and essentially all gas exiting the right heating compartment <b>50</b> flows into the right gas flow channel <b>142</b>R.

0045A left blower <b>150</b>L is suitably positioned in the left gas flow channel <b>142</b>L, e.g., adjacent its upper end, for circulating gas along a gas flow path through the left heating compartment <b>46</b>. In particular, gas from the blower <b>150</b>L enters the top plenum <b>110</b>; flows via respective left side and intermediate openings <b>130</b>, <b>134</b> in the top panel <b>66</b> down into the left and intermediate gas plenums <b>72</b>, <b>102</b>; flows via the gas flow openings <b>120</b> in the left and right panels <b>54</b>, <b>58</b> into the left heating compartment <b>46</b>; and exits the compartment via the openings <b>124</b> in the back panel <b>62</b> into the left gas flow channel <b>142</b>L for flow back to the blower <b>150</b>L.

0046Similarly, a right blower <b>150</b>R is suitably positioned in the right gas flow channel <b>142</b>R, e.g., adjacent its upper end, for circulating gas along a gas flow path through the right heating compartment <b>50</b>. In particular, gas from the right blower <b>150</b>R enters the top plenum <b>110</b>; flows via respective right side and intermediate openings <b>130</b>, <b>134</b> in the top panel <b>92</b> down into the right and intermediate plenums <b>98</b>, <b>102</b>; flows via the gas flow openings <b>120</b> in the left and right panels <b>80</b>, <b>84</b> into the right heating compartment <b>50</b>; and exits the compartment via the openings <b>124</b> in the back panel <b>88</b> into the right gas flow channel <b>142</b>R for flow back to the right blower <b>150</b>R.

0047Referring to <figref idref="DRAWINGS">FIGS. 9 and 10</figref>, a left heater <b>160</b>L is provided in the top plenum <b>110</b> generally at a location over the left heating compartment <b>46</b> for heating gas from the discharge of the left blower <b>150</b>L. Similarly, a right heater <b>160</b>R is provided in the top plenum <b>110</b> generally at a location over the right heating compartment <b>50</b> for heating gas from the discharge of the right blower <b>150</b>R. Alternatively, the heaters <b>160</b>L, <b>160</b>R can be placed immediately upstream from the blower inlets. By way of example but not limitation, each heater can comprise one or more electric resistance heating elements.

0048Referring to <figref idref="DRAWINGS">FIG. 11</figref>, a suitable support system <b>170</b> is provided for supporting food in each compartment at adjustable or non-adjustable levels within the compartment. In the illustrated embodiment, the support system <b>170</b> includes one or more supports <b>174</b>, each of which comprises horizontal rods <b>176</b> having ends sized for reception in the openings <b>120</b> in the side walls panels of the heating compartment, and one or more food holders <b>180</b> (e.g., trays or racks) supported by the rods. The rods <b>176</b> are removable so that each holder <b>180</b> is adjustable up and down in the heating compartment, as needed or desired, simply by inserting the rods in a different set of side wall openings <b>120</b>.

0049Desirably, each heating compartment <b>46</b>, <b>50</b> has a side-to-side width of no more than about 14 inches, exemplary dimensions being anywhere in the range of 4-14 inches (e.g., 4, 6, 8, 10, 12, or 14 inches). The relatively narrow width of each compartment <b>46</b>, <b>50</b> insures that hot gas entering the heating compartment via the left and right side openings <b>120</b> contacts the entire surface of each food product in the compartment, even the portions toward the middle of the compartment. The shorter distances required for gas flow results in good thermal heat transfer to the food and reduced temperature differential across the food (i.e., more uniform heating of the food).

0050Desirably, the openings <b>120</b> in the left and right side walls <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> of each heating compartment <b>46</b>, <b>50</b> are spaced a substantial distance rearward from the open front of the compartment to create a gas dead zone <b>200</b> at the front of each heating compartment extending substantially an entire height of the compartment and a full side-to-side width of the compartment. The zone <b>200</b> has a dimension in front-to-rear direction of at least 2 in., e.g., 2, 3, 4, 5, or 6 in. or more. The gas dead zone <b>200</b> is illustrated in <figref idref="DRAWINGS">FIG. 3</figref>. The gas dead zone <b>200</b> is also illustrated in <figref idref="DRAWINGS">FIG. 13</figref> in the heating compartment <b>50</b>. The gas dead zone <b>200</b> of this embodiment has a generally rectangular horizontal cross-section. In other words, a depth <b>200</b>D of the gas dead zone <b>200</b> is substantially constant across the full side-to-side width of the compartment <b>50</b>. The gas dead zone <b>200</b> may have different shapes, as discussed in more detail below. During operation of the oven <b>20</b>, this zone <b>200</b> is substantially free of moving gas generated by the oven. The zone <b>200</b> acts as a thermal barrier for preventing substantial loss of heat from the heating compartment <b>46</b>, <b>50</b>. As a result, there is no need for a door at the front of the compartment, making access to the compartment more convenient for loading and unloading of food.

0051The gas flow into and out of each heating compartment <b>46</b>, <b>50</b> is closely controlled by the pattern and size of gas openings <b>120</b>, <b>124</b> in the walls of the compartment. A representative arrangement of openings <b>120</b>, <b>124</b> is described below for an oven in which each of the left and right heating compartments has a height of about 15.0 in., a width of about 8.0 in., and a depth of about 19.0 in.

0052<figref idref="DRAWINGS">FIG. 4</figref> illustrates the left panel <b>54</b> defining the left side wall of the left heating compartment <b>46</b>. The gas flow openings <b>120</b> in the panel <b>54</b> are arranged in four vertical arrays A<b>1</b>-A<b>4</b> spaced at different distances D<b>1</b>-D<b>4</b> from the front of the heating compartment <b>46</b>, e.g., 3.5 in., 8.0 in., 13.5 in., and 15.5 in., respectively. (D<b>1</b> corresponds to the depth of the aforementioned gas dead zone <b>200</b>.) Each array A<b>1</b>-A<b>4</b> of openings comprises a matrix of columns and rows extending from adjacent the top of the panel <b>54</b> to adjacent the bottom of the panel. The width of the array A<b>1</b> (i.e., the number of columns in the matrix) varies in the vertical direction to form a series of relatively wide vertically-spaced clusters C<b>1</b>-C<b>3</b> of openings. The widths of the second, third, and fourth arrays A<b>2</b>-A<b>4</b> are identical (two columns per array). The openings have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Other dimensions are possible. Further, while the openings shown in the drawings are of the same size, they may differ in size.

0053<figref idref="DRAWINGS">FIG. 5</figref> illustrates the right panel <b>58</b> defining the right side wall of the left heating compartment <b>46</b>. The gas flow openings <b>120</b> in the panel <b>58</b> are arranged in four vertical arrays A<b>5</b>-A<b>8</b> spaced at different distances D<b>5</b>-D<b>8</b> from the front of the heating compartment <b>46</b>, e.g., 3.5 in., 8.0 in., 13.5 in., and 15.5 in., respectively. (D<b>5</b> corresponds to the depth J of the aforementioned gas dead zone <b>200</b>.) Each array A<b>5</b>-A<b>8</b> of openings comprising a matrix of columns and rows extending from adjacent the top of the panel <b>58</b> to adjacent the bottom of the panel. The width of the array A<b>5</b> (i.e., the number of columns in the matrix) varies in the vertical direction to form a series of relatively wide vertically-spaced clusters C<b>4</b>-C<b>6</b> of openings. The clusters C<b>4</b>-C<b>6</b> are staggered vertically with respect to the clusters C<b>1</b>-C<b>3</b> of the left panel <b>54</b> to provide more uniform gas flow into the heating compartment <b>46</b>. The widths of the arrays A<b>6</b>-A<b>8</b> are identical (two columns per array). The openings have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Other dimensions are possible. Further, while the openings shown in the drawings are of the same size, they may differ in size.

0054<figref idref="DRAWINGS">FIG. 6</figref> illustrates the left panel <b>80</b> of the right heating compartment <b>50</b>. The gas flow openings <b>120</b> in the panel <b>80</b> are arranged in four vertical arrays A<b>9</b>-A<b>12</b> spaced at different distances D<b>9</b>-D<b>12</b> from the front of the heating compartment <b>50</b>, e.g., 3.5 in., 8.0 in., 13.5 in., and 15.5 in., respectively. (D<b>9</b> corresponds to the depth of the aforementioned gas dead zone <b>200</b>.) Each array A<b>9</b>-Al<b>2</b> of openings comprises a matrix of columns and rows extending from adjacent the top of the panel <b>80</b> to adjacent the bottom of the panel. The width of the array A<b>9</b> (i.e., the number of columns in the matrix) varies in the vertical direction to form a series of relatively wide vertically-spaced clusters C<b>7</b>-C<b>9</b> of openings. The widths of the arrays A<b>6</b>-A<b>8</b> are identical (two columns per array). The openings <b>120</b> have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Other dimensions are possible. Further, while the openings shown in the drawings are of the same size, they may differ in size. In the illustrated embodiment, the openings <b>120</b> in the panel <b>80</b> have the same pattern and size as the openings <b>120</b> in the right panel <b>58</b> of the left heating compartment <b>46</b>.

0055<figref idref="DRAWINGS">FIG. 7</figref> illustrates the right panel <b>84</b> of the right heating compartment <b>50</b>. The gas flow openings <b>120</b> in the panel <b>84</b> are arranged in four vertical arrays A<b>13</b>-A<b>16</b> spaced at different distances D<b>13</b>-D<b>16</b> from the front of the heating compartment <b>50</b>, e.g., 3.5 in., 8.0 in., 13.5 in., and 15.5 in., respectively. (D<b>13</b> corresponds to the depth of the aforementioned gas dead zone <b>200</b>.) Each array A<b>13</b>-A<b>16</b> of openings comprises a matrix of columns and rows extending from adjacent the top of the panel <b>84</b> to adjacent the bottom of the panel. The width of the array A<b>13</b> (i.e., the number of columns in the matrix) varies in the vertical direction to form a series of relatively wide vertically-spaced clusters C<b>10</b>-C<b>12</b> of openings. The clusters C<b>10</b>-C<b>12</b> are staggered vertically with respect to the clusters C<b>7</b>-C<b>9</b> of the left panel <b>80</b> of the right heating compartment <b>50</b> to provide more uniform gas flow into the heating compartment. The widths of the arrays A<b>14</b>-A<b>16</b> are identical (two columns per array). The openings <b>120</b> have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Other dimensions are possible. Further, while the openings shown in the drawings are of the same size, they may differ in size. In the illustrated embodiment, the openings <b>120</b> in the panel <b>84</b> have the same pattern and size as the openings <b>120</b> in the left panel <b>54</b> of the left heating compartment <b>46</b>.

0056In general, the gas flow openings <b>120</b> in the left and right panels <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> of each heating compartment <b>46</b>, <b>50</b> are arranged and sized such that gas is delivered substantially uniformly into the heating compartment in a vertical direction from adjacent the top wall <b>66</b>, <b>92</b> of the heating compartment to adjacent the bottom wall <b>70</b>, <b>96</b> of the heating compartment, and such that gas is delivered substantially uniformly into the heating compartment from a location generally immediately rearward from the gas dead zone <b>200</b> to the back wall <b>62</b>, <b>88</b> of the heating compartment. The pattern and size of the openings <b>120</b> will vary according to such factors as the height, width, and depth dimensions of the heating compartment <b>46</b>, <b>50</b>, the number and vertical spacing of the food supports <b>174</b> in the compartment, and the velocity and volume of the gas flowing through the compartment.

0057<figref idref="DRAWINGS">FIG. 8</figref> illustrates the back panels <b>62</b>, <b>88</b> defining the back walls of the left and right heating compartments <b>46</b>, <b>50</b>, respectively. In the illustrated embodiment, the back panels <b>62</b>, <b>88</b> are integrally formed as one piece of sheet metal. In other embodiments, they may be formed as separate panels. The openings <b>124</b> in the left panel <b>62</b> are arranged in a first array A<b>17</b> providing communication between the left heating compartment <b>46</b> and the left gas flow channel <b>142</b>L of the back plenum <b>106</b>, and the openings <b>124</b> in the right panel <b>88</b> are arranged in a second array A<b>18</b> (identical to the first array A<b>17</b> in this embodiment) providing communication between the right heating compartment <b>50</b> and the right gas flow channel <b>142</b>R of the back plenum <b>106</b>. Each of the arrays A<b>17</b>, A<b>18</b> comprises five vertically-spaced groups of openings, and each group comprises a matrix of columns and rows covering a major portion of the back wall of a respective compartment. The openings have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Other dimensions are possible.

0058<figref idref="DRAWINGS">FIG. 10</figref> illustrates the top panels <b>66</b>, <b>92</b> defining the top walls of the left and right compartments <b>46</b>, <b>50</b>, respectively. Each group of side openings <b>130</b> includes a plurality of rectangular openings (three such openings being shown) for flow of gas from the top gas plenum <b>110</b> to respective side gas plenums <b>72</b>, <b>98</b>. The rear and center openings <b>130</b> closest the blowers <b>150</b>L, <b>150</b>R are smaller than the forward opening <b>130</b> farthest from the blowers to provide for a more uniform distribution of gas from the top plenum <b>110</b> to respective side plenums <b>72</b>, <b>98</b>. The group of intermediate openings <b>134</b> includes a plurality of rectangular openings (four such openings being shown) for flow of gas from the top gas plenum <b>110</b> to the intermediate gas plenum <b>102</b>. The side and intermediate openings <b>130</b>, <b>134</b> may vary in number and shape.

0059In the illustrated embodiment, the left and right heating compartments <b>46</b>, <b>50</b> are of the same size. However, it will be understood that heating compartments may vary in size with respect to one another. Regardless of size, however, the arrangement of the gas flow openings <b>120</b>, <b>124</b> should be such that the gas moving through the compartment has good heat transfer contact with the food substantially uniformly over the entire surface of the food in the compartment.

0060The left and right blowers <b>150</b>L, <b>150</b>R used in the two-compartment oven described above, may be tangential blowers, mounted side-by-side in a double housing such that the gas is discharged from the blowers through openings in a vertical flange <b>210</b> projecting up from the top panels <b>66</b>, <b>92</b> (<figref idref="DRAWINGS">FIG. 9</figref>). By way of example but not limitation, each blower may have an impeller diameter of 65 mm, a static pressure in its discharge plenum of about 0.036 IWC, and generate a gas flow rate of 165 cubic feet per minute.

0061Also, by way of example, each of the left and right heaters <b>160</b>L, <b>160</b>R may include a first relatively longer finned electric heating element <b>214</b> extending widthwise of the oven and a second relatively shorter electric heating element <b>216</b> spaced rearward from and generally parallel to the first element. The elements <b>214</b>, <b>216</b> of each heater <b>160</b>L, <b>160</b>R are secured to a respective top panel <b>66</b>, <b>92</b> and extend between the side and intermediate openings <b>130</b>, <b>134</b> of the panel above a respective heating compartment <b>46</b>, <b>50</b>. Other locations are possible. In one example, each heating element <b>214</b>, <b>216</b> has a power output of 500 watts, for a total output of 1000 watts per heater <b>160</b>L, <b>160</b>R, but this power output will vary according to the heating requirements of the oven.

0062Desirably, the oven has a suitable control system <b>230</b> for operating the oven. The system is housed in a control housing <b>234</b> secured to the front <b>38</b> of the oven housing <b>22</b>. The control system <b>230</b> includes an on/off power switch <b>238</b> and an operator input <b>240</b> for inputting desired operational information such as compartment temperature, heating time, and specific programs for heating (e.g., rethermalizing) and/or holding food in the oven. The control system <b>230</b> also includes a processor (not shown) for processing such information and controlling the blowers <b>250</b>L, <b>250</b>R and heaters <b>260</b>L, <b>260</b>R accordingly. It is preferable (although not essential) to configure the system such that the operation of the blowers <b>150</b>L, <b>150</b>R may be controlled independent of one another, and such that the operation of the heaters <b>160</b>L, <b>160</b>R may be controlled independent of one another. This allows each heating compartment <b>46</b>, <b>50</b> to be operated in a “modular” fashion independent of one another for greater flexibility in the use of the oven. By way of example, different foods may be heated in different heating compartments. Further, the number of compartments used at any given time may be tailored to meet the demand.

0063A fan <b>250</b> is provided for circulating air through the control system housing <b>234</b> to cool the various electronic components of the control system.

0064In a second embodiment (not shown), the oven <b>20</b> has a configuration similar to the first embodiment (<figref idref="DRAWINGS">FIGS. 1-11</figref>) but is altered to have a modified circulation of gas into and out of the compartments <b>46</b>, <b>50</b>. In particular, gas flows into the compartments <b>46</b>, <b>50</b> through the openings <b>120</b> in respective side walls <b>54</b> and <b>84</b>, and gas flows out of the compartments through the openings <b>120</b> in respective side walls <b>58</b> and <b>80</b> as well as through the openings <b>124</b> in the back panels <b>62</b>, <b>88</b>. Thus, gas flows into each compartment <b>46</b>, <b>50</b> through one wall <b>54</b>, <b>84</b>, and flows out of each compartment through two walls <b>58</b>, <b>80</b>, <b>62</b>, <b>88</b>.

0065The structure of the second embodiment is different from the embodiment described above in that the second embodiment lacks the intermediate openings <b>134</b> that enable communication between the top gas plenum <b>110</b> and the intermediate gas plenum <b>102</b>. The second embodiment has additional openings <b>124</b> in the back panels <b>62</b>, <b>88</b> that are disposed inboard of the side walls <b>58</b> and <b>80</b> to enable communication between the intermediate gas plenum <b>102</b> and the space between the vertical partitions <b>140</b> in the back gas plenum <b>106</b>. In addition, openings are provided in the vertical partitions <b>140</b> to enable communication among the space between the partitions and the left and right flow channels <b>142</b>L, <b>142</b>R.

0066Referring to the left heating compartment <b>46</b>, gas flow generated by the blowers <b>150</b>L, <b>150</b>R enters the top gas plenum <b>110</b>; flows via the left side openings <b>130</b> in the top panel <b>66</b> down into the left gas plenum <b>72</b>; flows via the gas flow openings <b>120</b> in the left panel <b>54</b> into the compartment <b>46</b>; and exits the compartment via the openings <b>120</b> in the right panel <b>58</b> and the openings <b>124</b> in the back panel <b>62</b>. Gas flow is returned to the blower <b>150</b>L via the left gas flow channel <b>142</b>L, which collects gas flow directly from the openings <b>124</b> in the back panel <b>62</b> and from the openings <b>120</b> in the side wall <b>58</b> through the intermediate gas plenum <b>102</b> and the space between the vertical partitions <b>140</b>.

0067Referring to the right heating compartment <b>50</b>, gas flow generated by the blowers <b>150</b>L, <b>150</b>R enters the top gas plenum <b>110</b>, flows via the right side openings <b>130</b> in the top panel <b>92</b> down into the right gas plenum <b>98</b>; flows via the gas flow openings <b>120</b> in the right panel <b>84</b> into the compartment <b>50</b>; and exits the compartment via the openings <b>120</b> in the left panel <b>80</b> and the openings <b>124</b> in the back panel <b>88</b>. Gas flow is returned to the blower <b>150</b>R via the right gas flow channel <b>142</b>R, which collects gas flow directly from the openings <b>124</b> in the back panel <b>88</b> and from the openings <b>120</b> in the side wall <b>80</b> through the intermediate gas plenum <b>102</b> and the space between the vertical partitions <b>140</b>.

0068In the second embodiment, the arrangement of the gas flow openings <b>120</b>, <b>124</b> may vary to accomplish a desired gas movement through the compartments <b>46</b>, <b>50</b> to impart good heat transfer contact with the food substantially uniformly over the entire surface of the food in the compartments. For example, in one test, 75% of the openings in the rear panels <b>62</b> and <b>88</b> shown in <figref idref="DRAWINGS">FIG. 8</figref> were absent or blocked. Other arrangements of the gas flow openings <b>120</b>, <b>124</b> may be used to impart desired gas movement through the compartments <b>46</b>, <b>50</b> to impart good heat transfer contact with the food substantially uniformly over the entire surface of the food.

0069In a third embodiment, the oven <b>20</b> has a configuration similar to the first embodiment but has modified side wall panels. A representative modified side wall panel <b>54</b>′, <b>80</b>′ is illustrated in <figref idref="DRAWINGS">FIG. 12</figref>. In general, the third embodiment is different from the first embodiment in that the side wall panels of the third embodiment have at least some louvered gas flow openings <b>120</b>L that direct gas exiting the left, right, and intermediate gas plenums <b>72</b>, <b>98</b>, and <b>102</b> through the louvered openings toward the rear of the heating compartments <b>46</b>, <b>50</b>. The louvered openings <b>120</b>L assist in preventing substantial loss of heat from the heating compartments <b>46</b>, <b>50</b> to ambient through the open fronts of the compartments. As a result, there is no need for a door at the front of each compartment.

0070The side wall panel illustrated in <figref idref="DRAWINGS">FIG. 12</figref> is configured for use as the left side panel <b>54</b>′ of the left side heating compartment <b>46</b> and/or the left side panel <b>80</b>′ of the right side heating compartment <b>50</b>. The corresponding right side panels <b>58</b>′, <b>84</b>′ (not shown) are generally a mirror image of the illustrated panel <b>54</b>′, <b>58</b>′, but may be different.

0071The gas flow openings <b>120</b>, <b>120</b>L of the panel <b>54</b>′, <b>80</b>′ are arranged in three vertical arrays A<b>19</b>-A<b>21</b> spaced at different distances D<b>17</b>-D<b>19</b> from the front of the heating compartment <b>46</b>, e.g., 1.0 in., 5.0 in., and 14.5 in., respectively. Each array A<b>19</b>-A<b>21</b> of openings comprises a matrix of columns and rows extending from adjacent the top of the panel <b>54</b>′ to adjacent the bottom of the panel.

0072The first array A<b>19</b> comprises the louvered gas flow openings <b>120</b>L. In the illustrated embodiment, the array comprises six columns and three rows of louvered openings <b>120</b>L. Louvers <b>120</b>L′ direct gas entering the compartment through the openings in a direction generally toward the rear of the compartment <b>46</b> and toward a centerline <b>250</b> (<figref idref="DRAWINGS">FIG. 13</figref>) extending from the front to the rear of the compartment. The louvers <b>120</b>L′ direct gas flow at an angle <b>275</b>′ (<figref idref="DRAWINGS">FIG. 13</figref>) less than or equal to seventy-five degrees with respect to the side wall panel <b>54</b>′. In the illustrated embodiment, the angle <b>275</b>′ is approximately forty-five degrees. Accordingly, the louvered openings <b>120</b>L assist in preventing substantial loss of heat from the heating compartment <b>46</b>. In addition, the louvered openings <b>120</b>L assist in directing heated gas toward the openings in the back wall panel <b>62</b> for return to the left gas flow channel <b>142</b>L. Other types, configurations, and arrangements of louvered or baffled openings <b>120</b>L may be used to accomplish desired gas flow.

0073The third embodiment has a gas dead zone <b>200</b>′ at the front of the compartment similar to the first embodiment, but the gas dead zone <b>200</b>′ in the third embodiment has a different shape than in the first embodiment. <figref idref="DRAWINGS">FIG. 13</figref> illustrates the gas dead zone <b>200</b> of the first embodiment in the right compartment <b>50</b> (i.e., the compartment <b>50</b> has left and right side wall panels <b>80</b>, <b>84</b> as described with respect to the first embodiment), and illustrates the gas dead zone <b>200</b>′ of the third embodiment in the left compartment <b>46</b> (i.e., the compartment <b>46</b> has left and right side wall panels <b>54</b>′, <b>58</b>′ as described with respect to the third embodiment). As discussed above, the gas dead zone <b>200</b> of the first embodiment has a generally rectangular horizontal cross-section. The depth <b>200</b>D of the gas dead zone <b>200</b> is substantially constant across the full side-to side width of the compartment <b>50</b>.

0074In the third embodiment, the gas dead zone <b>200</b>′ has a generally trapezoidal horizontal cross-section. This trapezoidal shape results from gas flowing from the louvered openings <b>120</b>L into the compartment. As in the first embodiment, the gas dead zone <b>200</b>′ extends substantially the entire height of the compartment <b>46</b> and the full side-to-side width of the compartment at the open front of the compartment. In addition, the gas dead zone <b>200</b>′ has a dimension (e.g., dimension <b>200</b>D′ shown in <figref idref="DRAWINGS">FIGS. 12 and 13</figref>) in the front-to-rear direction of at least at least 2 in., e.g., 2, 3, 4, 5, or 6 in. or more. However, the depth <b>200</b>D′ of the gas dead zone <b>200</b>′ (i.e., the front to rear dimension of the gas dead zone) varies across the side-to-side width of the compartment <b>46</b>. In particular, the depth <b>200</b>D′ tapers proximate the side wall panels <b>54</b>′, <b>58</b>′ from the open front toward the rear of the compartment <b>46</b> because of gas flow entering the compartment through the louvered openings <b>120</b>L. The gas dead zone <b>200</b>′ tapers at generally the same angle <b>275</b>′ at which gas flows from the louvered openings <b>120</b>L. Other embodiments may have gas dead zones of different or varying shapes.

0075As in the gas dead zone <b>200</b> of the first embodiment, the gas dead zone <b>200</b>′ is substantially free of moving gas generated by the oven during operation of the oven <b>20</b>. The gas dead zone <b>200</b>′ acts as a thermal barrier for preventing substantial loss of heat from the heating compartment <b>46</b>. As a result, there is no need for a door at the front of the compartment, making access to the compartment more convenient for loading and unloading of food.

0076Referring again to <figref idref="DRAWINGS">FIG. 12</figref>, the second and third arrays A<b>20</b> and A<b>21</b> comprise openings <b>120</b> of similar size and shape as the openings <b>120</b> of the first embodiment. For example, the openings <b>120</b> have a diameter of about 0.290 in., a vertical center-to-center spacing of about 0.50 in., and a horizontal center-to-center spacing of about 0.50 in. Varying numbers of arrays may be used, and arrays having different numbers or types of openings and different widths (i.e., different numbers of columns) may be used.

0077In a fourth embodiment, the oven <b>20</b> has a configuration similar to the third embodiment but has different side wall panels. A representative modified side wall panel <b>54</b>″, <b>58</b>″ of the fourth embodiment is illustrated in <figref idref="DRAWINGS">FIG. 14</figref>. Instead of having louvered openings, the modified side wall panel <b>54</b>″, <b>58</b>″ of the fourth embodiment has openings <b>120</b>C in at least one surface <b>300</b> of the side wall panel that is oriented toward the rear of the heating compartment <b>46</b>. In other words, the openings <b>120</b>C are provided in one or more surfaces <b>300</b> of the side wall panel <b>54</b>″, <b>58</b>″ that face or are angled toward the rear of the heating compartment <b>46</b>.

0078The gas flow openings <b>120</b>, <b>120</b>C of the panel <b>54</b>″, <b>58</b>″ are arranged in seven vertical arrays A<b>22</b>-A<b>28</b> spaced at different distances D<b>20</b>-D<b>26</b> from the front of the heating compartment <b>46</b>, e.g., 1.5 in., 3.5 in., 5.5 in., 6 in., 8 in., 12 in., and 14 in., respectively. Each array A<b>22</b>-A<b>28</b> of openings comprises a matrix of columns and rows extending from adjacent the top of the panel <b>54</b>″ to adjacent the bottom of the panel.

0079In the representative side panel <b>54</b>″, <b>58</b>″ illustrated in <figref idref="DRAWINGS">FIG. 14</figref>, the panel has a corrugated section <b>350</b> proximate the open front of the oven <b>20</b>. The corrugated section <b>350</b> comprises ridges <b>351</b> extending vertically along the side wall panel <b>54</b>″, <b>58</b>″. Each ridge <b>351</b> comprises a surface <b>300</b> oriented generally toward the rear of the heating compartment and a surface <b>301</b> oriented generally toward the open front of the oven <b>20</b>. The openings <b>120</b>C of the first, second, and third arrays A<b>22</b>-A<b>24</b> are provided on the surfaces <b>300</b> oriented toward the rear of the heating compartment <b>46</b>. The surfaces <b>300</b> are oriented so that gas flowing from the openings <b>120</b>C is directed generally toward the rear of the compartment <b>46</b> and toward the centerline <b>250</b> extending from the front to the rear of the compartment. Gas flows from the openings <b>120</b>C at an angle <b>275</b>″ (<figref idref="DRAWINGS">FIG. 13</figref>) less than or equal to seventy-five degrees, more preferably sixty degrees, and more preferably forty-five degrees, with respect to the side wall panels <b>54</b>″, <b>58</b>″. In the illustrated embodiment, the angle <b>275</b>″ is approximately forty-five degrees. Other angles may be used. In addition, the surfaces <b>300</b> may be oriented differently so that openings <b>120</b>C in different ones of the surfaces direct gas flow toward the rear of the compartment <b>46</b> at different angles with respect to the side wall panel.

0080The gas dead zone <b>200</b>″ of this embodiment is similar to the gas dead zone <b>200</b>′ of the third embodiment (i.e., the side wall panels <b>54</b>″, <b>58</b>″ of the fourth embodiment installed in the compartment <b>46</b> would produce approximately the same gas dead zone <b>200</b>′ as in the third embodiment). The gas dead zone <b>200</b>″ has a depth <b>200</b>D″ that varies along the side-to-side width of the compartment <b>46</b>. More specifically, the depth <b>200</b>D″ tapers proximate the side wall panels <b>54</b>″, <b>58</b>″ from the open front toward the rear of the compartment <b>46</b> because of gas flow entering the compartment through the openings <b>120</b>C. The gas dead zone <b>200</b>″ tapers at generally the same angle <b>275</b>″ at which gas flows from the openings <b>120</b>C. Other embodiments may have gas dead zones of different or varying shapes. As in previous embodiments, the gas dead zone <b>200</b>″ acts as a thermal barrier for preventing substantial loss of heat from the heating compartment <b>46</b>.

0081Referring again to <figref idref="DRAWINGS">FIG. 14</figref>, the fourth to seventh arrays A<b>25</b>-A<b>28</b> may comprise openings <b>120</b> of similar size and shape as the openings <b>120</b> of the embodiments described above. Varying numbers of arrays may be used, and arrays having different numbers or types of openings and different widths (i.e., different numbers of columns) may be used.

0082In a fifth embodiment, illustrated in <figref idref="DRAWINGS">FIGS. 15 and 16</figref>, the oven <b>20</b> has a configuration similar to the first embodiment but includes baffles <b>400</b> within the heating compartments <b>46</b>, <b>50</b> on the side wall panels <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> for deflecting gas exiting the holes <b>120</b> downward into an open top <b>180</b>′ of a food holder <b>180</b> (e.g., tray). The openings <b>120</b> in the side wall panels <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> may have various arrangements. In the illustrated arrangement, clusters C<b>13</b> and C<b>14</b> of openings <b>120</b> on each side wall panel <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b> extend along substantially the entire depth of the heating compartments <b>46</b>, <b>50</b>. The baffles <b>400</b> overhang at least some of the openings <b>120</b> to direct gas flowing from those openings into the heating compartment <b>46</b> generally downward to contact food within the holder <b>180</b>. The baffles <b>400</b> are desirably positioned vertically within the heating compartments <b>46</b>, <b>50</b> with respect to the support system <b>170</b> in contemplation of characteristics (e.g., height, width) of the desired food holders <b>180</b> to be used so that gas deflected downward by the baffles <b>300</b> is directed from a suitable height and at a suitable angle <b>450</b> (<figref idref="DRAWINGS">FIG. 16</figref>) so that the gas flows through the open top of the holder and contacts the food in the holder when the holder is positioned on the support system <b>170</b>. The angle <b>450</b> may be generally between five and seventy-five degrees with respect to the side wall panel. The angle is more desirably between twenty and sixty degrees, and more desirably between forty and fifty degrees. In the illustrated embodiment, the angle <b>450</b> is approximately forty-five degrees.

0083The illustrated baffles <b>400</b> extend approximately the entire front-to-rear depth of the heating compartments <b>46</b>, <b>50</b>, but baffles of other lengths may be used. In addition other types of baffles may be used. For example, louvered openings may be used to direct flow of gas as desired.

0084In a sixth embodiment, illustrated in <figref idref="DRAWINGS">FIG. 17</figref>, the oven <b>20</b> again has a configuration similar to the first embodiment but is different in that the oven includes vanes <b>500</b> positioned and supported within the left, right, and/or intermediate gas plenums <b>72</b>, <b>98</b>, <b>102</b> to counteract forward velocity of gas flowing within the plenums to prevent the gas from breaching the gas dead zone <b>200</b> in the front of the compartments <b>46</b>, <b>50</b> after the gas flows into the compartments through the openings <b>120</b> in the side wall panels <b>54</b>, <b>58</b>, <b>80</b>, <b>84</b>. <figref idref="DRAWINGS">FIG. 17</figref> illustrates representative vanes <b>500</b> positioned and supported in the intermediate plenum <b>102</b>.

0085As explained above with respect to the first embodiment, gas from the left blower <b>150</b>L travels along the top gas plenum <b>110</b>, flows into the intermediate gas plenum <b>102</b>, and then flows into the heating compartment <b>46</b> via the openings <b>120</b> in the right side wall panel <b>58</b>. Some gas entering the heating compartment <b>46</b> may tend to flow toward the open front of the oven <b>20</b> as a result of the gas molecules having residual velocity in that direction from the blower <b>150</b>L. The vanes <b>500</b> desirably substantially counteract residual forward velocity to prevent gas molecules entering the heating compartment <b>46</b> from breaching the gas dead zone <b>200</b> in the front of the compartment to prevent substantial loss of heat from the heating compartment. Moreover, the vanes <b>500</b> may be configured to turn the flow of gas toward the rear of the compartment <b>46</b> so that the gas molecules tend to flow toward the rear of the compartment upon entry into the compartment through the openings <b>120</b> in the right side wall panel <b>58</b>.

0086Gas dead zones as described herein may have different shapes in different embodiments. Although the gas dead zone <b>200</b> and the gas dead zones <b>200</b>′ and <b>200</b>″ have generally rectangular and generally trapezoidal horizontal cross-sections, respectively, other gas dead zones may have different horizontal cross-sections. For example, a gas dead zone may have a generally triangular horizontal cross section. In some embodiments, the gas dead zone has the same horizontal cross-section (e.g., rectangular or trapezoidal) over substantially the entire height of the heating compartment <b>46</b>, <b>50</b>. However, in other embodiments, the dimensions of the gas dead zone may vary over the height, across the width, and along the depth of the heating compartment <b>46</b>, <b>50</b>.

0087<figref idref="DRAWINGS">FIGS. 18-23</figref> show another embodiment of an air handling unit or oven of this invention, generally designated <b>500</b>. The oven <b>500</b> is similar in construction to the oven <b>20</b> of the first embodiment. The oven <b>500</b> comprises a housing <b>504</b> defining an oven cavity comprising a plurality of side-by-side heating compartments <b>508</b>. (Five such compartments <b>508</b> are shown but this number can vary.) Desirably, each heating compartment has a side-to-side width of no more than about 14 inches. Heated air is circulated through the compartments <b>508</b> in much the same manner as in the oven <b>20</b> of the first embodiment. As shown in <figref idref="DRAWINGS">FIGS. 19</figref>, <b>21</b>, and <b>22</b>, blowers <b>512</b> positioned at the upper end of a rear plenum <b>516</b> in the oven blow air over electric resistance heaters <b>520</b> positioned in an upper plenum <b>524</b> of the oven (see <figref idref="DRAWINGS">FIG. 19</figref>). The heated air flows down through openings <b>528</b> into plenums <b>534</b> at opposite sides of the heating compartments <b>508</b> and then into the compartments <b>508</b> through gas flow openings <b>540</b> in the left and right side walls <b>544</b>, <b>548</b> of the compartments (<figref idref="DRAWINGS">FIGS. 20-22</figref>). Air from the heating compartments <b>508</b> is exhausted into the rear plenum <b>516</b> through openings <b>550</b> in the back walls <b>556</b> of the compartments (see <figref idref="DRAWINGS">FIG. 20</figref>).

0088However, the oven <b>500</b> differs from the previous embodiments in that it has no dead zone at the open front <b>560</b> of each compartment <b>508</b>. Further, unlike prior art ovens, there is no air curtain at the open front <b>560</b> of each compartment. The gas flow openings <b>540</b> in the side walls <b>544</b>, <b>548</b> of the compartments are configured such that substantially all of the gas blowing into the heating compartment <b>508</b> is directed generally away from the open front <b>560</b> of the compartment. <figref idref="DRAWINGS">FIG. 23</figref> illustrates one such gas flow opening <b>540</b> in a respective side wall <b>544</b>, <b>548</b>. The opening <b>540</b> is generally oval in shape, having a longitudinal axis <b>564</b>, and comprises an angled nozzle <b>570</b> that directs air flowing through the opening at an acute angle <b>574</b> in the range of 10-45 degrees (e.g., about 15 degrees) relative to the side wall. Other gas flow opening configurations are possible.

0089Referring to <figref idref="DRAWINGS">FIGS. 19 and 19A</figref>, supports <b>580</b> are provided on the side walls <b>544</b>, <b>548</b> of the heating compartments <b>508</b> for supporting trays <b>582</b> at vertically spaced elevations in the heating compartment. The trays have outwardly projecting peripheral flanges <b>584</b> around their open tops. The flanges <b>584</b> are dimensioned to rest on the supports <b>580</b> such that trays hang down from the supports. Other supporting arrangements are possible. Further, the supports <b>580</b> are configured for supporting the trays at an upward inclination toward the back wall <b>556</b> of the heating compartment <b>508</b>. The angle of inclination <b>586</b> (e.g., 10-20 degrees) allows a user of the oven to readily observe the contents of the trays.

0090The gas flow openings <b>540</b> are grouped in a plurality of arrays <b>590</b> comprising vertical columns of openings and rows of openings <b>540</b> extending generally in front-to-back direction with respect to the heating compartment. The arrays <b>590</b> are spaced at vertical intervals at locations corresponding to the areas above the supports <b>580</b> and the open tops of the trays <b>582</b>. Further, the arrays <b>590</b> are configured to extend generally at the same angle of inclination <b>586</b> as the supports <b>580</b> and trays <b>582</b> (e.g., 10-20 degrees). Although each array <b>590</b> as a whole is upwardly inclined toward the back wall <b>556</b> of the compartment <b>508</b>, the longitudinal axis <b>564</b> of each individual opening <b>540</b> extends generally horizontally. The arrangement is such that heated air discharged through the gas flow openings <b>540</b> of each array <b>590</b> passes over the top of any tray supported immediately below the array and under the bottom of any tray supported immediately above the array. As a result, food in each tray is uniformly heated from above and below.

0091Generally horizontal arrays <b>596</b> of gas flow openings <b>540</b> are provided adjacent the lower ends of the side walls <b>544</b>, <b>548</b> of each heating compartment <b>508</b>. During operation of the oven <b>500</b>, heated air flowing through these arrays <b>596</b> of openings functions to warm cooler make-up air flowing into the heating compartments <b>508</b> via the open fronts <b>560</b> of the compartments.

0092Referring to <figref idref="DRAWINGS">FIGS. 18 and 19</figref>, an air deflector <b>600</b> is mounted adjacent the upper end of each heating compartment <b>508</b> for deflecting heated air into the heating compartment. In the illustrated embodiment, the air deflector <b>600</b> comprises a single rectangular transparent panel (also designated <b>600</b>) extending across the open fronts <b>560</b> of all five heating compartments <b>508</b>. Alternatively, a separate air deflector can be provided for each compartment. The deflector <b>600</b> is pivoted on brackets <b>606</b> at the front of the oven housing <b>504</b> for movement between a raised position (shown in phantom lines in <figref idref="DRAWINGS">FIG. 19</figref>) to enable removal of one or more trays <b>582</b> from a heating compartment or compartments <b>508</b> and a lowered operative position (shown in solid lines in <figref idref="DRAWINGS">FIG. 19</figref>) in which heated air rising in the heating compartments is deflected back into the compartments. This deflection reduces the escape of heated air from the oven, thus increasing efficiency and decreasing any negative impact escaping air might have on the surrounding environment. A holder <b>610</b> is provided on the deflector for holding a menu, instructions, or other material to be observed by a user of the oven.

0093Referring to <figref idref="DRAWINGS">FIG. 19</figref>, the open front of each compartment has an overall vertical height represented by the dimension <b>602</b>. The air deflector <b>600</b> is dimensioned such that, when in its lowered position, it has a vertical height represented by the dimension <b>604</b>. Desirably, the ratio of dimension <b>604</b> to <b>602</b> is less than one-half, and even more desirably no more than about one-third. As a result, when the deflector <b>600</b> is in its lowered position, it extends down over only the upper portion of the open front <b>560</b> of each heating compartment <b>508</b>.

0094In its lowered position, the air deflector panel <b>600</b> desirably rests on support members <b>614</b> adjacent opposite sides of the oven housing <b>504</b> (<figref idref="DRAWINGS">FIGS. 18 and 19</figref>). These support members <b>614</b> support the panel at an acute angle <b>620</b> (e.g., 15 degrees) sloping in a forward direction down and away from the open front <b>560</b> of each compartment <b>508</b>. This slope increases the volume of heated gas deflected by the panel back into the heated compartments. In other embodiments, the air deflector <b>600</b> may assume a substantially vertical orientation when in its lowered position.

0095<figref idref="DRAWINGS">FIGS. 24-26</figref> show another embodiment of an oven of this invention, generally designated <b>700</b>. The oven <b>700</b> is similar to the oven <b>20</b> of the first embodiment. Supports <b>704</b> are provided for supporting trays <b>708</b> in a generally horizontal orientation (with no substantial upward tilt). Gas flow openings <b>710</b> in the side walls of each heating compartment are configured in generally horizontal arrays at locations generally corresponding to the areas above the open tops of the trays <b>708</b>. Heated gas discharged through the openings <b>710</b> of each array <b>714</b> flows across the top of any tray <b>708</b> immediately below the array and flows across the bottom of any tray immediately above the array. Heated gas exits each heating chamber <b>720</b> through openings (not shown) in the back wall <b>724</b>, as described in previous embodiments.

0096When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

0097In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

0098As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.